Thirty male college undergraduate volunteers repeatedly tracked a segment of the Aetna Training Film, Traffic Strategy, with the Aetna Drivo-Trainer Station.. Simultaneously their eye movements were recorded. Simgle low doses of antihistamine (methapyrilene, .7 mg/kg) and tranquilizer (chlordiazepoxide, i.e., Librium, .2 mg/kg) were administered on different days in combination with placebo or ethyl alcohol (70 mg%). While there were no significant effects on these low doses on steering, accelerating, decelerating, or braking errors, there were significant effects of drugs on eye movements and blink rate. Chlordiazepoxide increased eye movements, alcohol suppressed eye movements, while synergistic combinations of alcohol with antihistamine and chlordiazepoxide had intermediate effects. The main effects of alcohol were to suppress large amplitude eye movements correlated with stimuli occurring in the periphery. There was a significant negative correlation between driving errors and the ratio of the frequency of long to short discursive eye movements. This suggests that a maladaptive effect of low alcohol concentrations may be to decrease detection of peripheral dangerous events when visula load is high, as in congested traffic. The antagonistic effects of alcohol combined with antihistamine or chlordiazepoxide suggests that a more thorough examination of the synergistic effects of these drugs should be made in terms of critical dose level, rate dependency, and tolrance effects.